Session: 03-11-01: Multifunctional Materials

Paper Number: 151461

151461 - Intrinsic Self-Healing in Vitrimeric Carbon Fiber Reinforced Polymer Composites at Micro and Macro Scales 

Material’s performance degrade over time due to accumulation of defects, and carbon fiber reinforced polymer (CFRP) composites are not an exception in this regard. Vitrimers, an emerging class of thermosetting polymers with exchangeable covalent bonds offers a remedy in this regard, in which the dynamic nature of the bonds allows for “resetting” the clock of damage accumulation in composites. In our study, aromatic thermosetting polyesters (ATSP), a high performance vitrimer, was chosen as the matrix in processing vitrimer CFRPs. We studied the longevity of the self-healing behavior over multiple healing cycles and also, we studied the healing of the interface in these composites. To assess the self-healing behavior, these vitrimeric CFRPs were tested via the double cantilever method, healed by exposing them to 280^oC for 2 hours, and retesting up to five healing cycles. From DCB testing, mode I fracture toughness was calculated over five healing cycles, and healing efficiency was determined per healing cycle from acquired values. The results demonstrated that there was complete healing after the first two healing cycles, and a gradual decline of healing from the third to the fifth healing cycle. The surface and internal morphology of the vitrimeric CFRPs closely resembled the virgin samples after two healing cycles. However, the integrity of the matrix and carbon fiber structure was gradually depleted from the third to the fifth healing cycles. This performance decline in the vitrimeric CFRP’s performance was further confirmed by reduced detection of carbon reinforcement components. These findings demonstrated that ATSP, an enhanced performance vitrimer, maintains intrinsic self-healing behavior amongst multiple healing cycles, while the interface between CFs and matrix maintains its integrity.

Presenting Author: Mohammad Naraghi Texas A&M University

Presenting Author Biography: Dr. Naraghi is a professor in the department of Aerospace Engineering, Texas A&M University.